JPS59197671A - Mud pump liner - Google Patents

Abstract

PURPOSE:To improve the wearproofness of an inner linear, by pouring a low melting point molten metal into a gap between a cast iron or steel-make outer liner and a ceramic-make inner liner, and molding it in one upon solidification. CONSTITUTION:Having assembled a cast iron or steel-make outer liner 02 and a cerami-make inner liner 01 temporarily inside a heating furnace 04, both liners are preheated up to the temperature required by heating elements 05 and 06. And, after a molten metal 03' is poured in from an inlet 07, the molten metal is cooled and solidified, then the inlet 07 is removed. As for a ceramic, it is large enough in compression strength but poor in tensile force so that it is important to know that it should be produced in a state of being so proper in compression stress to meet requirements for a mud pump liner on which large internal pressure is imposed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mud pump liner for supplying mud to a trench during drilling operations in oil and gas wells and geothermal wells.

The mantle pump used is of the piston type, and usually consists of a cylinder with a wear-resistant liner, a pair of pistons with a rubber lining, and a driving section thereof.

As shown in FIG. 1, the cylinder liner consists of an inner liner 1 made of high chromium cast iron and an outer liner 2 made of ordinary cast iron, and the inner liner 1 is shrink-fitted to the outer liner 2.

As described above, various efforts have been made to improve the wear resistance of the inner liner 1 in conventional mud pump cylinders, but the wear effect caused by particles in the mud is extremely large, and the lifespan is shortened by several hundred hours. It's finished.

On the other hand, the use of ceramics can be considered as one means of improving wear resistance.

The present invention takes this idea into account and provides a structure that meets the mechanical requirements of mud pumps at low cost.

That is, the present invention includes an outer liner made of cast iron or cast steel,
The present invention relates to a mud pump liner that has a ceramic inner liner and is formed by pouring a low melting point metal into the gap between the outer liner and the inner liner, solidifying it, and molding it as one piece.

An example of an embodiment of the liner of the present invention is shown in the second factor.

In Figure 2, 01 is a ceramic inner liner,
Alumina, silicon nitride, silicon carbide, etc. are used as the ceramic material. 02 is an outer liner, and the material used is carbon steel, cast steel, cast iron, etc. 03 is an intermediate layer of low melting point metal, and the materials are aluminum, zinc, and lead.

A metal having a melting point of 700° C. or lower, such as tin or an alloy thereof, is used.

FIG. 3 is a diagram showing an example of manufacturing the liner of the present invention shown in FIG. 2.

In Fig. 6, 04 is a heating furnace, 05 is an external heating element, 0
6 is an internal heating element, 07 is a molten metal inlet, and 06 is a low melting point metal molten metal. The external/internal heating elements 05 and 06 may be formed using electric heating, for example, or various other methods.

As for the manufacturing procedure, first, the inner liner 01 and the outer liner 02 are temporarily assembled in the heating furnace 04, and then preheated to the required temperature by the heating elements 05 and 06, and the molten metal 06' is injected from the injection port 07, and then cooled.

It is completed by solidifying and removing the injection port 07.

At this time, it is also possible to cool it using a cooling device (not shown) if necessary.

The preheating temperature is determined by the solidification temperature of the intermediate layer metal 03. It is sufficient if the temperature is higher than the temperature at which the intermediate deposit IA05 can flow into the required portion without solidifying. Even if it is overheated, there will be no harm, other than wasted heat dissipation due to solidification.

By the way, ceramic has a very high compressive strength,
Tensile strength is low. For items such as mud pump liners that are subject to large internal pressures, it is important to manufacture them to an appropriate compressive stress state. According to the great invention, it is possible to obtain a ceramic inner liner to which any residual stress is applied.

Since residual stress is determined by the difference in thermal expansion coefficients between the outer liner 02 and the inner liner 01 after solidification of the intermediate layer 05, it is desirable to select a metal for the intermediate layer 05 based on a combination of these two.

For example, the outer liner 02 is cast steel, the inner liner 0
As a result of various studies on the cases in which alumina, silicon nitride, and silicon carbide were selected as No. 1, as shown in the table below, the appropriate solidification temperatures were 420°C, 200°C, and 200°C, respectively, and the intermediate layer 06 metal and 1 - 46 parts of zinc and tin - 54 parts of lead
An appropriate example would be an alloy containing all parts.

Another method for obtaining such residual stress is shrink fitting. However, in the case of shrink fitting, it is necessary to machine the mating surfaces with high precision, but this method is inappropriate because it takes a long time to process materials that are difficult to machine, such as ceramics, to achieve the necessary precision. be.

However, in the present invention, there is no need to particularly process the bonding surfaces, making the process extremely easy.

As detailed above, according to the present invention, it is possible to (1) process the mating surfaces easily and therefore at low cost, and (2) provide residual stress that is optimal for the usage conditions of the ceramic. It can be used as a liner, which has a great effect on extending the life of the liner.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional mud pump liner, FIG. 2 is a diagram showing an embodiment of the liner of the present invention, and FIG. 3 is a diagram showing an example of manufacturing the liner of the present invention shown in FIG. 2. Sub-agents 1) Meifuku agent Ryo Hagiwara -

Claims (1)

[Claims] A mud pump liner that has an acta liner made of cast iron or cast steel and an inner liner made of ceramic, and is made by pouring a low melting point metal into the gap between the outer liner and the inner liner, solidifying it, and molding it as one piece.